1. Field of the Invention
The present invention relates to laser-scanning microscopes, and more particularly, to a laser-scanning microscope and a microscope observation method in which an observation laser beam and a manipulation laser beam are multiplexed and irradiate a specimen via the same objective lens.
This application is based on Japanese Patent Application No. 2006-132674, the content of which is incorporated herein by reference.
2. Description of Related Art
In the related art, there are known laser-scanning microscopes that are provided with an observation-laser-beam light source and a manipulation-laser-beam light source and that two-dimensionally scan an observation laser beam and a manipulation laser beam on a specimen using independent scanning units.
For example, US Patent Application, Publication No. 2002/0020800 discloses a laser-scanning microscope provided with a movable focusing mechanism for changing the focal position of a manipulation laser beam, enabling the focal position of the manipulation laser beam to be changed along an optical axis direction. US Patent Application, Publication No. 2002/0020800 also discloses using the manipulation laser beam as optical tweezers. More specifically, it is disclosed that, by radiating the manipulation laser beam at various different manipulation sites by operating scanning (deflecting) means for the manipulation laser beam in a plane parallel to the focal plane of the objective lens, those manipulation sites are gripped with the optical tweezers.
In a laser-scanning microscope like that described above, it is desired to acquire a three-dimensional fluorescence image of the specimen by gripping a plurality of sites on the specimen and three-dimensionally scanning the observation laser beam while keeping this state, that is, while keeping the gripping sites gripped by the optical tweezers. However, when the specimen is irradiated with an observation laser beam and a manipulation laser beam via the same objective lens, moving the objective lens or a stage on which the specimen is mounted to change the focal position of the observation laser beam causes the focal position of the manipulation laser beam to also move together with this movement.